Frederik arnold holleman



(No Model.)

P. A. HOLLEMAN.

- AIR BRAKE.

No. 405,705. PatentedJune 25. 1889. I

N. PETERS, Pholwl-ilhagrzphen Washiqgion. D. C.

UNITED STATES PATENT OFFICE.

FREDERIK ARNOLD HOLLEMAN, OF OISTERVVYK, NETHERLANDS.

Al R- BRAK E.

SPECIFICATION forming part of Letters Patent No. 405,705, dated June 25, 1889.

Application filed January 10, 1889. Serial No. 295,968. (No model.) Patented in England May 2, 1888, No. 6,549.

To aZZ whom it may concern:

.Be it known that I, FREDERIK ARNOLD HOLLEMAN, a subject of the King of the Netherlands, residing at ()isterwyk, Kingdom of the Netherlands, have invented certain new and useful Improvements in Air-Brakes, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanyin g drawings, and to letters and figures of reference marked thereon, similar letters indicating like parts throughout.

This, my said invention, relates more particularly to the valves used in connection with air-brakes, such as those described in my specification No. 377,198, dated January 31, 1888, and my British specification No. 6,549, dated May 2, 1888.

Said invention consists in certain modifications in the construction of said air-brakes, all of which are hereinafter fully described, and set forth in the claims.

Figure 1 is a sectional elevation of my improved controlling-valve, showing the valve in its normal position. Fig. 2 is a sectional elevation showing the valve in the position it occupies when the brakes are moderately applied. Fig. 3 is a sectional elevation show ing the position of the valve when the brakes are applied with full force. Fig. 4. is a plan view of the airport 1).

In the drawings, A refers to the valve-casing, which consists of a metal cylinder internally screwed at its ends to receive the end pieces B B, which are formed upon their inner surfaces with inwardly-projecting abutments 1) b, which by their determined length limit the travel of the valve. Upon the upper part of the casing A is the boss 0, in which is screwed the pipe 0, connecting the controlling-valve with the auxiliary air-reservoir. The under side of the valve-casing A has a boss 0, in which is screwed the pipe 0, which is in connection with the main air-supply pipe. A suitable air-port D (having its upper part formed in the shape as shown, Fig. 4) is in direct communication by way of the pipe d with the brake-cylinder. The

valve-casing A has also an air-port E, adapted to receive the screw-piece E formed with an aperture adapted to be closed by a ball-valve F, inclosed in a metal-wire basket f, which establishes or cuts off the communication between the air-port E, the channel E", and the pipe (Z of the brake-cylinder.

Accurately but freely fitted into the casing A is the reciprocating valve G, which consists, essentially, of a cylinder having midway its length a division G. Said. valve is prevented from moving in a rotary direction by the screw-pin a, projecting inwardly through the side of the valve-casing A, and loosely entering the groove 9 in the side of the valve G.

Upon the under side of the valve G is formed the passage or channel G which, when the valve is in the position shown in Fig. 1, al lows air to escape from the brake-cylinder to the exhaust-port a, which is open to the atmosphere.

In the division G is an aperture G closed by a valve H, which is held open by the spiral spring 72, its opening being limited by the pin h.

A small aperture g in the upper part of the valve G establishes a communication between the inner side of the valve G and the groove g on its upper side, in order to allow compressed air from c to exercise a constant full pressure upon the valve G, and thereby attaining an air-tight junction between the lower side of the valve G and the inside of the casing A. Another aperture q is situated in the lower part of the valve G, and is adapted to coincide with the air-port E, when the valve G assumes the position as shown, Fig. 3.

In order to insure a perfect air-tight fitting of the valve G, and at the same time to allow of a free reciprocating movement thereof, a suitable packing-ring, of any desired construction, is fitted in a groove formed around the periphery of the said valve, as shown at 9 A spring I brings the valve G back in the position, as shown in Fig. 2, when air ceases to press it toward the head The manner in which my improied controlling'valve operates isas follows: hen compressed air is admitted to the valve-casing from the main air-supply pipe through the pipe 0, the valve G, under the pressure of the incoming air, is moved to the right toward the brakes slightly.

the head 13, as shown in Fig. 1. The compressed air now passes freely through the aperture G and the open valve H and enters the auxiliary reservoir by way of the pipe 0. Slight differences in the main air-pipe and the reservoir are equalized through the valve H and aperture G The valve G remains in the position shown in Fig. 1. until the pressure in the main air-supply pipe is suddenly reduced or falls below the pressure in the res ervoir, when the valve II will close the aperture or port G The valve G, by reason of the greater pressure of the air in the reservoir, moves toward the abutment Z), at the same time cutting off the communication between D and a, Fig. 2, and uncovering the air-port D, Fig. 3, allowing the compressed air from the reservoir to freely enter the brake-cylinderby way of the pipe cl. The peculiar shape of the upper part of the port D allows a small quantity of air to enter the brake-cylinderbefore the port is fully opened, thus applying in the reservoir by the .outflow of air to the brake-cylinder has been nearly reduced to an equal pressure to that in the main airpipe, the movement of the valve G toward the abutment b ceases, and when it is equalized the valve G will be brought back to the position, Fig. 2, by the pressure of the spring I, at the same time cutting off the communication between C and D, and the valve G, covering the port D, holds the brakes applied with every desired force. When it is necessary to speedily apply the brakes, the

pressure in the main pipe is suddenly much reduced, and the valve G will be moved toward 1), Fig. 3, allowing air coming from the reservoir to flow to the brake-cylinder, together with air coming from the main pipe through the aperture 9 and the air-passage E E to the port D, until the pressure in said main air-pipe equals that in the brake-cylinder,

thus effecting a speedy discharge of the main pipe throughout its length. hen the pressure in the main falls below that in the brake cylinder, the valve F prevents a return of the air to the main pipe, accelerated braking being thus attained, Fig. In order to re lease the brakes airis again admitted through 0' to the valve G, which is thereby returned to the position shown in Fig. 2 by the spring I, and to the position, Fig. 1, by the overpressure in O, and the brake-cylinders are discharged through D G a. Communication between the main pipe and the auxiliary reservoir being again established this com- As soon as the pressure.

munication cannot arise through c g E E D O, as in Fig. 3, since the valve Gis pressed by the spring I to the position shown in Fig. 2 before air coming from C can open the valve F against the pressure of air in the brake-cylinder. The products of condensation in the described valve cannot accumulate within the casing, as they are completely exhausted therefrom; hence there is no danger of the valve becoming inoperative in cold weather, and as the valve is more or less lubricated by petroleum no water can find a lodgment between the valve and its casing by capillary attraction.

Having now described my said invention, what I claim is 1. The herein-described controlling-valve for air-brakes, comprising a cylinder A, having its ends closed with end pieces B B, form ed upon their inn er surfaces with inwardly-proj ectin g abutments Z) Z), a pipe 0', in c011- nection with the main supply-pipe, a pipe 0, in connection with the auxiliary reservoir, an airport D, a pipe d, in connection with the brake-cylinder, the air channel or passage E, communicating with the airport E, a ballvalve F, closing this air -port, the channel g, formed in the upper part of the valve G, the exhaust-port a, in the lower part of the casing, and the screw-pin projecting from the inner surface of the casing A, all substantially as and for the purposes hereinbefore set forth.

2. The combination, with the casing A and its connections, of the valve G, adapted to reciprocate within said valve-casing A, and consisting of a cylinder having a division G, a packing-ring g encircling the periphery of said valve, a groove g,in which is adapted to slide the screw-pin a, the air-channel G and the air-port in its under side, the air-port g in its upper side, the air-port G in the division G, said port G being closed by the Valve H, which-is held open by the spring h and limited in its opening by the pin h, and y the spring I, fitted around the abutment b, all substantially as and for the purposes hereinbefore specified, and illustrated in the drawings hereunto annexed.

In testimony that I claim the foregoing I have hereunto set my hand, this 12th day of December, 1888, in the presence of two witnesses.

FREDERIK ARNOLD HOLLEMAN.

Witnesses:

N. FELIX, L. H. RoLFFs. 

